Micro Piezo print heads are used in Epson inkjet printers for all applications.

In March 1993, Epson launched its groundbreaking Epson Stylus 800 inkjet printer. This was the first product to include Micro Piezo technology, which has since become established as one of Epson company's core technologies, and the Micro Piezo print head, which is the core component of Epson inkjet printers. Twenty years on, we take a two-part look at the story behind the development of this incredible technology, and its ongoing evolution.

The monochromeEpson Stylus 800 inkjet printer

Sense of crisis

In the 1980s, the majority of Epson printers were SIDM* (serial impact dot matrix) printers. But the market for such products gradually began to decline due to expanding use of personal computers and the increasing use in the office of laser and other printers based on electrophotographic technologies. Epson executives realized that the potential decline in the market for one of their main products posed a significant risk to the company, and they set about researching inkjet and other printing technologies.

Epson's management was aware that competitors had already successfully launched to market inkjet printers with both reasonable performance and price

Epson had launched its first inkjet printer, the SQ-2000, as early as 1984, and followed this with the HG series of inkjets. However, these products struggled to make an impact on the market, and Epson's management was divided about the company's direction.

Breaking through the wall

With inkjet printer development not proceeding as expected and company executives concerned, Epson began researching a completely different type of print head. The young engineer put in charge of this essential project was Minoru Usui, now global president of Epson.

The SQ-2000 inkjet printer,launched in 1984

The big issue facing Usui's team surrounded the piezo element that was included on the glass print heads used in those original Epson inkjets. The theory was that electrical power applied to the element caused the element to change shape. This in turn generated mechanical pressure that forced the ink out. However, despite applying 100 volts the team was unable to generate sufficient power to fire an ink droplet. The team knew that they had to do something to improve the piezo, but were unable to make the necessary breakthrough. Usui and his team felt they had hit a wall.

It was then Usui and his team had their lucky break. Usui noticed that a new type of actuator - a key component that converts electrical power to mechanical motion - they had been considering for driving dot matrix printers could also be used in inkjet printers. Looking back, Usui commented, "I still remember the elation I felt as I listened to that explanation. Although the structure was different to what we had been working on, we could achieve what we wanted by making some minor changes. I knew instantly that it would be possible to accurately fire the ink droplets with only a small voltage."

This was in 1989. At last understanding how to solve the issues they had been facing, Usui and his team went all out to develop the new print head they believed could hold the secret for Epson's future growth.

* SIDM printers are still sold to this day, with Epson holding world-leading market share as of June 2013.